I received my Ph.D. from Duke University in 2001 (working with James S. Clark). While at Duke, my field work took me to the Coweeta Hydrologic Laboratory in western North Carolina (an LTER site), where I studied differences among temperate tree species in seed dispersal, seed banking and density-dependent mortality, and how those differences contribute to diversity-maintenance.  I then worked with David Tilman at the Cedar Creek Ecosystem Science Reserve (another LTER site associated with University of Minnesota). There, I studied how declining diversity and species identity influences productivity and the impacts of global change on seed production. In a subsequent postdoc at University of California, Santa Barbara (working with Jonathan Levine), I focused on the factors that allowed Mediterranean annual grasses to dominate over the diverse California annual grasses and forbs as well as the contributions of niche and neutral processes to the coexistence of Serpentine annuals.  I arrived at University of Washington in 2006.

I am a plant community ecologist broadly interested in: 1) the maintenance of species diversity and 2) how global change (climate change, invasive species, nitrogen deposition, etc) alters the structure and function of plant communities.  I approach questions of interest with observational studies, manipulative experiments, and statistical modeling, working in a variety of habitats (North Carolina, Minnesota, California, Washington). Check out the Research page on this website for more information.

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I am interested in plant species response to climatic change. In particular, I study 1) the processes driving range dynamics and 2) how patterns, in particular, deviations from the norm, can provide new insights. Rather than considering variability to be noise, I consider variability to reflect previously unidentified or overlooked factors. My goal is to use deviations in expected patterns in plant species distribution and traits to understand and, more realistically, predict response to climatic change. To address this goal I use observation data, field experiments, and statistical modeling.

I am interested in the relationship between climate and plant species distributions, and how these distributions might shift with climate change. I study these issues in the high elevation plant communities of Mount Rainier National Park. As elevation increases in these mountains, dense coniferous forests give way to a mosaic of tree 
patches and meadows known as subalpine parkland, which then give way to alpine meadows dominated by low stature plants, which finally transition to bare land and ice. These communities contain a diversity of species, including several of conservation concern.

The boundaries of the different zones are strongly linked to climate, and with climate change trees will probably establish in the subalpine and alpine meadows, while meadow species will probably colonize bare ground. However, this general upward movement will likely reduce the geographic extent of the meadows since there is less land at higher elevations. In addition, the poor quality of the soil the alpine plants would be colonizing could strongly limit establishment rate, while trees moving into meadows would not face such a restriction.  Thus, subalpine and alpine meadows could experience severe declines in extent that may result in species extirpations.

The research questions I’m interested in are 1) which climate variables are most important for determining the geographic ranges of high elevation vegetation zones and how will climate change affect these ranges? 2) what are the relevant spatial scales of these climate-vegetation relationships? 3) how might dispersal and establishment limitations constrain the abilities of plant species to migrate in response to climate change? I am addressing these questions with a combination of modeling, observational studies and field experiments.

I also work on outreach efforts at Mount Rainier. As part of this work, I have produced a report on the impacts of climate change on the Park.

Graduate Student - Elli Jenkins Theobald      

I am excited to have joined the Hille Ris Lambers lab in 2010!  While at UW, I plan to study plant and pollinator communities on Mount Rainier.  Broadly, I am interested in the biological implications of climate change.  Specifically, is mismatch between plants and pollinators likely to happen if the phenologies of these organisms shift?  And what role does pollination play in determining the distribution of species? Using the elevational gradient on Mount Rainier I will try to answer these questions and assess two of many potential biological implications of a warmer world. 

I am coming back to Washington State after four years teaching middle school and high school in Oakland, California.  Before teaching, I studied Biology and Environmental Science at Colby College in Maine.  As an undergrad I was involved in a number of research projects including surveying vegetation recovery on Mount Saint Helens, investigating the pollination regime of a Costa Rican weed, and studying habitat-specific behavior in Black Capped Chickadees.  As a part of the Hille Ris Lambers lab, I have the opportunity to build on both my research and teaching experiences, and I am thrilled to be here!

Graduate Student - Ailene Kane Ettinger

I am interested in plant ecology and conservation, in particular how anthropogenic factors affect plant communities. Global climate change is one of the most pervasive anthropogenic forces on the planet, and species are predicted to migrate, adapt, or go extinct as our climate warms.  In order to understand how plant communities may shift with projected warming, we need to know what factors drive species range limits. My dissertation research involves studying altitudinal range limits of trees growing on Mt. Rainier, the relative importance of biotic versus abiotic factors in affecting tree distributions, and how their distributions will shift in the future.  I focus on the roles of climate and competition in limiting ranges of three dominant conifer species along an elevational gradient at Mt. Rainier.   Range limits of plants have often been attributed to climactic factors, such as drought and cold tolerance; few studies have focused on how species interactions, such as competition, affect trees across their ranges.
 
I joined the Hille Ris Lambers Lab in 2007 to pursue a PhD in biology. Prior to coming to UW, I worked in ecological research and conservation biology projects in Maine, Costa Rica, and throughout New England. In addition to climate change research, I am passionate about many other areas of plant ecology and conservation, including urban ecology, restoration, conservation planning, and “citizen science” programs involving nonscientists in the scientific process.

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Website

Can the invasion of non-natives affect pollinator services? Historically dominated by forbs and bunchgrasses, Puget Trough prairies are now undergoing extensive invasion by sod-forming grasses. Where they are locally abundant, these exotic grasses alter the spatial distribution of native forbs, whose flowers offer pollen and nectar resources to prairie pollinators. Simultaneously, they alter community structure by replacing patchy bunchgrass tufts with dense stands of exotic grass, important because the bare ground between tufts offers habitat for ground-nesting bees. 

 My current project uses historical flowering data from prairie herbarium specimens, in combination with contemporary plant abundance data, to identify potential seasonal gaps in pollinator resources in prairies with a range of exotic grass densities.  I am complementing this approach with field data on pollinator limitation of native prairie forbs in more- and less-invaded sites and on relative contributions of native and exotic floral resources to key pollinators.